Grid-leak cell circuit



Patented Apr; 24, L928.

- HAROLf) HARDY silicon, "or JOHANNESBURG, SOUTH AFRICA, ASSIGNOR 'ro MIN- ERALS SEPARATION NORTH AMERICAN CORPORATION OF MARYLAND.

'Pnocnss FOR THE PRODUCTION or ems.

Application filed September 14,1922. Serial No. 588,127.

I This" invention relates to the production pf gas, andis herein disclosed as a process for the 'produotionof a gas consisting largely of hydrogen sulphide, carrying carbon dioxide and some other substances in gaseous and vapor form and which is especially adapted to'be" used for treating ores for [froth-flotation purposes.

As disclosed herein, the gasf may be produced from relatively cheap and naturally occurring sulphides, such as sulphide of iron, or the sulphides of copper which form the common ores-of copper. For this purpose it is advantageous to have the sulphide material fairly finely ground, since the reactions to a'large extent seem to be in the nature'of surface reactions.

To 'obtainthe desired type of gas and to prevent the evolution of sulphur vapor, the sulphide Ior sulphur-bearing material is inixedjwith carbon and then heated to a relatively low temperature but sufficiently to cause areaction between it and steam, which *is now blown through it. The temperature "may then be raised gradually to the maxi-' mum suitable forthe reaction, discharging the gases all'the time from a hotter part of the zone of reaction. This procedure enablesany deleterious results to be avoided 'f'whichmight"arise from passlng over free sulphur or over v relatively cooler sulphurbearing material the hydrogen-sulphidebearinggas which" has been formed. These results maybe obtained either intermittentlyv orcontinuously',

thr features dadvantages Willherelimiter ppear. i a

' In ,the accompanying drawings Figure 1 shows-anapparatus suitable for evolvingfthe hydrogen-sulphide-bearmg gas ""fr'omjaclosed retort"andcol1ect1ng 1t. The

ret rtybe gfafterwards recharged to produce another lot: of (gas,

{"Figurefl" is fa 'sectional side view of an we e thej' continuous production of uref 'is Tatai -sew th ppa t I *"F'guret4usasectional'end view of the In t efprofcedure is "carried ion in'ithe apparatus showfifin Figure I," steam is gen- Iae'ratedinj.aboiler 1 and conveyed by a pipe gnawi gt g test taster team is con CORPORATION, or NEW YORK, N. Y., A w

Above this mixture is placed a second wire netting '6, and above the netting 6 a layerof lime, or limestone, or residual lime from a previous run, this lime material amounting to about 10% of the total charge below the wire netting 6. It, has been found that these various forms of lime are almost equally eflioient for the purpose which. will be described more in detail later'on. When the retort is thus filled, its top 7 is bolted down by bolts 8 passing through flanges 9 of a usual form. A. pipe 10 through the top 7 conveys away the gases produced. It has been found advisable to have the total content of sulphur in the mixture beneath the netting 6 less than 30% of the mixture. If the sulphur-bearing material used produces a mixture of greater sulphur content, it has been found advisable to mix inert material therewith, such as quartz or the gangue of ores. 1

The retort 4. is externally heated and to this end is shown as standing within an open topped furnace 11, with charcoal packed around the retort between the retort and the walls of the furnace 11. The furnace is. preferably started by igniting the charcoal at the top and the steam turned on by 0 ening the valve 3. The steam is prefextent 's'ubjectedto the heat thereof with 'superheating action. I-have found in the use of this apparatus that the retort pro-' *duced the best gaswhen heated by the furnace .11 so that its temperature varied from about400 C. at the bottom near'the netting 5, to about" 700 0.1m thetop near the furnaces.

' erab y, carried through a short section 12 of the pipe 2 within the furnace and to some atented Apr. 24, 1928..

GRID-LEAK CELL CIRCUIT.

Application filed October 22, 1924. Serial No. 745,211.

This invention relates to radio circuits in which a light-sensitive cell takes the place oi'a grid leak in an oscillation generator circuit, and has for its principal object such an adjustment of the component parts as will stop and start oscillation in accord with the light and dark condition of the cell.

With this and other objects, the invention consists of the employment and arrangement of the several elements described in the following specifications, illustrated in the drawing, and particularly pointed out in the claim.

In the drawings A is a light-sensitive cell; B a three-element tube; and C as oscillationgenerating coil coupling.

With the several parts adjusted for oscillation of the circuit when light falls on the cell, the oscillation willinstantly cease when the light is cut ofif, because of the increase in the resistance of the cell. The output of the oscillating circuit is, therefore, intermittent, the intermittance depending upon the order of the light falling on the cell.

No means for intermittently illuminating the cell is shown as this is no part of the invention and not essential to an understand;

ing of its operation.

What claim, is I The combination with an electron valve, of'a circuit including input and return conductors connected respectively with the grid and filament electrodes of the valve, a variable stopping condenser in series with said input conductor, and a resistance leak in said input conductor shunted about the condenser and comprising a light sensitive cell.

y In testimony whereof I have affixed my signature.

CHARLES FRANCIS JENKINS. 

